Global Observer makes first hydrogen-powered flight

12 January, 2011

SOURCE: Flight International

BY: Gayle Putrich

Washington DC

AeroVironment's newest unmanned aircraft has successfully made the transition to hydrogen power, the company says, starting with a 4h test flight at Edwards AFB in California. The manufacturer launched flight testing of the high-altitude, long-endurance design under battery power last August.

"Global Observer has moved quickly from development and testing toward demonstrating mission-ready, affordable persistence," says AeroVironment chief executive Timothy Conver. "The speed with which we have achieved this milestone reflects the benefits of an effective government-industry partnership."

Global Observer is designed to fly for five to seven days at a time, at altitudes of 55,000-65,000ft (16,800-19,800m) carrying a 172kg (380lb) communications and intelligence, surveillance and reconnaissance payload. The UAV burns liquid hydrogen in an internal-combustion engine to drive a generator and produce electricity to power four propellers and charge the back-up batteries.

Ground testing of the hydrogen system began last November with an uninterrupted seven-day mission cycle in a test chamber that simulated the temperature and pressure changes of a high-altitude climb, loiter and descent, the company says.

AeroVironment will ultimately deliver two Global Observers to the Pentagon under a joint capability technology demonstration (JCTD) programme. The company and the military hope to move beyond the initial $120 million JCTD, becoming a programme of record within the US government between 2012 and 2014.

The US Special Operations Command is "working" to find more funding for Global Observer, Conver told analysts in December.